Grease gun



Aug. 13, 1929. R. RAPELLIN 1,724,617

GREASE GUN Filed Oct. 1, 192'7 Patented Aug. 13, 1929.

UNITED STATES PATENT OFFICE.

RENE EAPELLIN, or Los ANGELES, CALIFORNIA. 'I

GREASE GUN.

Application filed Octoberl 1, 1927. Serial No. 223,385.

1 an improved grease gun wherein there is a barrel within Whicha piston having a threaded piston rod is reciprocable, and to provide an improved construction for establishing and disconnecting a threadeden gagement'between the piston rod and the barrel. By this construction it is possible on disconnecting the threaded engagement b etween the barrel and the piston rod, to move` the piston and piston rod bodily without rotating it, and whenthe fluid to be discharged from the barrel is a relatively light oil, the grease gun can be used/in this manner for discharging the'contents of the gun.y When a relatively heavy grease is employed, the threaded engagement between the piston rod and the vbarrel may be established, and in such position, in order to advance the piston, it is necessary to rotate the piston rod, thus developing 'a great mechanical advantage 1 enabling the grease to be discharged from the gun. f

The improved grease gun contemplates a novel means 'for establishing and disconnecting the threaded engagement between the barrel and the grease gun. -An object i cally pointed out in the appended claims,v

of the invention vis to provide a construction wherein thereV are threaded means adapted to be placed in engagement with the threaded piston rod, and a rotatable cap on the barrel is capable of being rotated to hold the threaded means in engagement with the piston rod. With theforegoing and otherobjects in view which will be made manifest in the following detailed description and specifireference is had to the accompanying drawings for an illustrative embodiment. of the invention, wherein:

Figure 1 is a .view in side elevation of the improved grease ggun,A parts being broken away and shown in vertical section, the grease gun being shown in that position wherein there is a threadedv connection provided between the barrel and the threaded piston rod. l

F'ig.2 isa partial viewfin vertical 'section' similar to Figure l, illustrating thev threaded,

connection between the barrel andthe rod as having been disconnected. :L f

Fig. 3 is a vertical section takenupon the line 3--3 upon Figure 2'.

piston Fig. 4' is a horizontal section vtaken upon.

the line 4.-4upon Figure 1. 'f Fig. 5 is a horizontalsection taken 'upontheV line 5-5 upon Figure 2.

. Fig. Y6 is a perspective View lofthe rotatv` able ca on thebarrel;y g v Fie". fis a'vertical sectionthrough a part ofthegreasegun. H i

` Referring to the accompanyingdrawings wherein similar reference characters designate similar partsthrou'ghout, the improved grease gun consists of a barrel 10 into whichA extends a threaded piston rod 11.1- A piston 12 is secured tothe lowerfend' of the piston rod by means of a set screw 13.: On the upper end of the piston-rod- 11 :there is screwed a handle 14 which isheldin place by a set screw 15. Onthe bottom of the barrel there is threaded a cap 16 having a threaded nipple 17 to which a -hose maybe connected. The cap 16 'can be removed from the-barrel v10 for relling purposes. Within the barrel 10 adjacent its upper end there is positioned a member generally'designated at 18, shown in Figure 'Yr-This member `has a disc-like bottom V19 which snugly fits the l interiorof thev barrel and which is secured theretoby means of screws20.; Above the bottom 19 and on opposite sides of thecentralaperture 21, there'extend two armsr 22 which are separated from each other byl di-` ametricalslots23. These slots have parallel sides and are of slightly less width than the diameter `of the threaded piston rod 11. The exterior surfaces of the ,tWo arms 22 arecylind'ricaland threaded, and they are y connected at their upper `ends by means of an externally threaded 'ring 24- astened to the arms by ymeans of screws 25. v The ring 24 merely serves to strengthen the armsr and hold them in' place about the piston rod. Y.

exterior surfaces threadedv with 'threads adapted to form continuations of the threads on the exterior surfaces of the arms 22. The

'blocks are of such thickness that when the site the blocks 26, there are fastened sockets 27 which are fastened Vin place by means of screws 28. Pins or screws 29 extend through the sockets and through the barrel and have their inner ends screwedv intoV tapped holes in the blocks 26. Coil springsl 30 are compressed between the heads of the screws 29 andthe sockets, urging the screws outwardly, and consequently, urging the `blocks 26- to be drawn outwardlyV or disengaged from the piston rod=11. OnV the upper end ofthe barrel there is positioned ay cap 31 which has two* dependingV di'ametrically opposite 'arms 32. These arms present semi-cylindrical interior surfaces which` are spaced .from each other a. distance equal to the diameter across the' arms 22L These armsv are somewhat wider than the blocks 26- and have formed' on their opposed surfaces, threads. which are complementary to the threads on the outside of the ring 24" and on thevo'utsideof the-arms 22' andi the blocks 26. lNhile the arms-32 are wider than lthe blocks 26, they are somewhat narrower than the arms 22l so that-they can be causedy to vassume the position shown" in Figure 5, wherein they completely uncover the exterior surfaces of the locks'26',. enabling the springs 30l to withdraw' the blocks from engagement with' the pistony rod 11.1 'The arms 32- are relatively thin, and betweenl these arms and the interior of the barrel"10',the cap carries depending'arms' 33 which arel relatively heavy so as to be strong and rugged. These arms carry screws 34 which are adapted to be tightened into `engagement with the lower endsof arms 32. so as to'keep the arms 32 engagement with the upstanding arms 22 and to take up wear on the'threads.v On the top surface of the disc-like bottom 19, therey are formed projections 35 `opposite the slots 23'. Thesek projections areadapted to be engaged by the bottomsl of the blocks 26 so that the outward movement of the blocks will-jbe limited thereby.'

'The 'operation of the improved grease gun is as follows:

I In order to establish the threaded connec-l tion between thel barrel' 10 and the threaded pistoni .rodv 1.1i, the heads of the two screws 29 are pressed inwardly, causing the blocks 26 tov slidel into threaded engagement with the piston rod. When in this position, the exterior* surfaces of the blocks form continuations of the cylindrical surfaces on the outside of the arms 22, andv while the blocks are in this position the cap 31 can be rotated on the barrel vfrom the position shownL in Figures 2 and 5, into the position shown in Figures l and 4. In this position, the arms 32 are over the ends or outside surfaces of the blocks 26 and hold them in engagement with the piston rod against the action of the springs 30. When the threaded engagement is thus established, in order to advance the piston 12 to discharge the contents C, it is necessary to rotate the piston rod by the handle 14. When, however, it is possible to discharge the contents of the barrel by manually shifting the piston", pistonV rod and handle without rotation, the cap 31 is reversely rotated so that the arms32' will? move from the position shown in Figure 4' to theposition shown in. Figure'l 5, enabling the blocks 26 to be drawn out of eniga-gement with the piston rod 11v by the springs 30. In this position, the piston rod can be caused toi slide through the-member.

18, the ring 24' and' the cap 31. It will be appreciated that in order to 'establish the threaded' connectionv between:v the` barrelf and piston rod, it is merely necessary to press the heads of the screws 29 toward each other-and then rotate the cap 31;` and in order to disconnect the threaded connection, it is merely necessary to reversely rotatel thecapl'.- The vrotation of the cap 31T can be limi-ted by means of screws 36 and' 37 on the barrel, adaptedto be; engaged by one ofthe-strengthening arms From-the above described construction, it

will be appreciated that the improved grease i means fory guiding said`threaded`*mem ber,

said cap carrying means adapted to engage the threaded members and hold them in engagement with the said screw, and arms carried by said cap, said arms having adjusted screws mounted thereon engageable upon said means as and for the purpose described.

2. A construction associated with a feed screw comprising guide means through which the feed screw slidably extends, threaded members slidable through openings in the guide means adapted to engagethe-feedl screw, and rotatable means threadedly mounted upon the guide means adapted to engage the backs of thel threaded members upon rotav tion to hold themin engagement with the feed screw. p

3, A construction associated With a feed screw comprising guide means through which to hold them in engagement with the feed the feed screw slidably extends, threaded screw, and spring means urging the threadmembers slida-ble through openings in the ed members out of engagement with the feed 10 guide means adapted to engage the feed screw, screw.

5 and rotatable means threadedly mounted In testimony whereof I have signed my upon the guide means adapted to engage the name to this specification. backs of the threaded members upon rotation REN' RAPELLIN. 

